Asier Illarramendi has completed his move to Real Madrid, signing a six-year contract after passing his medical with the club.

The 23-year-old midfielder was today unveiled at the club's Santiago Bernabeu stadium, putting pen to paper on his contract alongside club president Florentino Perez.

The Spanish giants yesterday agreed to pay the midfielder's buy-out clause with Real Sociedad. The overall cost, made up of the clause and the associated tax penalties, to Madrid for the player is reported to be in the region of €39million (£33.6million).

The signing of the 23-year-old, who helped Sociedad earn a Champions League berth for the forthcoming season, is further evidence of Madrid investing in youth.

Illarramendi was a member of the Spain side which recently won the European Under-21 Championship in Israel.

He rose to prominence at Sociedad last season, playing an important role as they finished fourth in the Primera Division, securing a place in the Champions League in the process.

Illarramendi becomes Madrid's fourth signing of the summer - following the arrivals of Isco and Dani Carvajal from Malaga and Bayer Leverkusen respectively, while midfielder Casemiro's loan deal from Sao Paulo has also been made permanent.

The quartet will work next season under new Madrid boss Carlo Ancelotti, who has moved from Paris St Germain to replace Jose Mourinho.